... chert, firm sandstone, and firm anhydrite and so on.4.According to your request, all sorts of products can ... 5 1/2”),142.8mm(5 5/8”),149.2mm(5 7/8”)152.4mm(6”),155.5mm( ... 5/8”),349.2(13 3/4”)374.6(14 3/4”)381(15”),393.7(15 1/2 ... /2”),508(20”),558(22”),609.6(24”)660.4(26”) Steel tooth(IADC)111, 121,131117,124 ... L/C at sight, western unionProducts show 8 3/4" IADC 527 Kingdream drill bits for rocks HAS series ...